restore_snapshot · Memory Engine MCP: Risk & Policy

WHAT IT DOES

What restore_snapshot does on Memory Engine

AI agents use restore_snapshot to create or update resources in Memory Engine — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Memory Engine environment.

WHY IT NEEDS A POLICY

Why restore_snapshot needs a policy

This tool modifies the current session state by restoring previously saved data (emotional states, conversation context, memories). While it reconstructs prior state rather than creating new data, it is a Write operation because it alters the active session configuration.

From the tool's definition Tool name 'restore_snapshot' and description indicating it restores a previous session snapshot. The description states it is called at session start to restore state from a prior session.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

restore_snapshot Rate-limited

restore_snapshot stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "restore_snapshot": {
      "limits": [
        {
          "counter": "restore_snapshot_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Memory Engine, so you can run agents against it safely.

FAQ

Questions about restore_snapshot

What does the restore_snapshot tool do? +

前回セッションのスナップショットを復元する。セッション開始時に呼ぶ。. It is categorised as a Write tool in the Memory Engine MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on restore_snapshot? +

Register the Memory Engine MCP server in PolicyLayer and add a rule for restore_snapshot: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Memory Engine. Nothing to install.

What risk level is restore_snapshot? +

restore_snapshot is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit restore_snapshot? +

Yes. Add a rate_limit block to the restore_snapshot rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block restore_snapshot completely? +

Set action: deny in the PolicyLayer policy for restore_snapshot. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides restore_snapshot? +

restore_snapshot is provided by the Memory Engine MCP server (kagioneko/memory-engine-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.